In my previous patents, magnetic jewelry closures including mechanical safety features have been described. Such closures are satisfactory for their intended purposes, but are not suitable for all purposes for which jewelry closures are used. Also the mechanical safety features on these closures have not been as simple or economical to make as the jewelry closures described herein.
Known magnetic closures include that shown in Mizuno, U.S. Pat. No. 3,129,477. Such a magnetic closure, without a safety feature may have a perceived lack of strength due to the absence of a conventional closure. U.S. Pat. No. 3,263,444, to Di Croce, describes a hinged ring having a magnetic closure in FIG. 3 thereof. This closure also has no safety features. U.S. Pat. Nos. 3,566,616; 4,763,490; 4,790,148; 4,991,409; and 5,136,858 each show hinged rings having mechanical closures only which are relatively complex and/or expensive to make as a dual closure is not provided for added safety.